I have just installed my gentoo on an acer travelmate 4150. Everything works fine, except the fact that i cannnot enable DMA. I have tried everything, and now i copy my tests with hdparm,and kernel config to see if you could help me:

That chip can be dificult to set up for DMA. If you look in lspci you will see its listed as a SATA driver but it controls your CD-ROM as /dev/hdc.
It has two configuration settings in the kernel and posiibly your BIOs too. Try adding in SCSI support, SCSI Disk Support and under Low Level SCSI Drivers, SATA and PIIX._________________Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

i own a travelmate 4101 wlmi and after some kernel changes i got dma running here is my config

Quote:

# ATA/ATAPI/MFM/RLL support
#
CONFIG_IDE=y
CONFIG_BLK_DEV_IDE=y

#
# Please see Documentation/ide.txt for help/info on IDE drives
#
# CONFIG_BLK_DEV_IDE_SATA is not set
# CONFIG_BLK_DEV_HD_IDE is not set
CONFIG_BLK_DEV_IDEDISK=y
CONFIG_IDEDISK_MULTI_MODE=y
# CONFIG_BLK_DEV_IDECS is not set
CONFIG_BLK_DEV_IDECD=y
# CONFIG_BLK_DEV_IDETAPE is not set
# CONFIG_BLK_DEV_IDEFLOPPY is not set
# CONFIG_BLK_DEV_IDESCSI is not set
CONFIG_IDE_TASK_IOCTL=y

#
# IDE chipset support/bugfixes
#
CONFIG_IDE_GENERIC=y
# CONFIG_BLK_DEV_CMD640 is not set
# CONFIG_BLK_DEV_IDEPNP is not set
CONFIG_BLK_DEV_IDEPCI=y
CONFIG_IDEPCI_SHARE_IRQ=y
# CONFIG_BLK_DEV_OFFBOARD is not set
CONFIG_BLK_DEV_GENERIC=y
# CONFIG_BLK_DEV_OPTI621 is not set
# CONFIG_BLK_DEV_RZ1000 is not set
CONFIG_BLK_DEV_IDEDMA_PCI=y
# CONFIG_BLK_DEV_IDEDMA_FORCED is not set
CONFIG_IDEDMA_PCI_AUTO=y
# CONFIG_IDEDMA_ONLYDISK is not set
# CONFIG_BLK_DEV_AEC62XX is not set
# CONFIG_BLK_DEV_ALI15X3 is not set
# CONFIG_BLK_DEV_AMD74XX is not set
# CONFIG_BLK_DEV_ATIIXP is not set
# CONFIG_BLK_DEV_CMD64X is not set
# CONFIG_BLK_DEV_TRIFLEX is not set
# CONFIG_BLK_DEV_CY82C693 is not set
# CONFIG_BLK_DEV_CS5520 is not set
# CONFIG_BLK_DEV_CS5530 is not set
# CONFIG_BLK_DEV_HPT34X is not set
# CONFIG_BLK_DEV_HPT366 is not set
# CONFIG_BLK_DEV_SC1200 is not set
CONFIG_BLK_DEV_PIIX=y
# CONFIG_BLK_DEV_IT821X is not set
# CONFIG_BLK_DEV_NS87415 is not set
# CONFIG_BLK_DEV_PDC202XX_OLD is not set
# CONFIG_BLK_DEV_PDC202XX_NEW is not set
# CONFIG_BLK_DEV_SVWKS is not set
# CONFIG_BLK_DEV_SIIMAGE is not set
# CONFIG_BLK_DEV_SIS5513 is not set
# CONFIG_BLK_DEV_SLC90E66 is not set
# CONFIG_BLK_DEV_TRM290 is not set
# CONFIG_BLK_DEV_VIA82CXXX is not set
# CONFIG_IDE_ARM is not set
CONFIG_BLK_DEV_IDEDMA=y
# CONFIG_IDEDMA_IVB is not set
CONFIG_IDEDMA_AUTO=y
# CONFIG_BLK_DEV_HD is not set

maybe you need some more changes but here it works, and i dont think that your notebook has much differences.

Thank you schlummerkissen, but yours kernel configuration don't work for me. I can't enable dma for the disk and dvd so my notebook it's very slow and I can't burn anythings in my dvd-rw. For information my disc it's /dev/hdc and the dvd it's /dev/hdd. I tried to disable in the kernel all ide drivers as suggested in this thread: http://forums.gentoo.org/viewtopic-t-356273-start-0-postdays-0-postorder-asc-highlight-.html
but I can't boot y gentoo due to kernel panic.
Any suggsuggestion?

I had similar problem with my Acer Aspire 5012. The solution was enabling (built-in into kernel) ATI IXP chipset (AIR the only not compiled in by default!).
I didn't change other settings. And it started working.
Maybe try enable all chipsets?

maybe you try first to run a live-cd like kanotix and test if dma mode runs there.
Then you could compare the config of the life-cd and the loaded modules etc. with your gentoo-kernel.
May be it could help you.

I tried enable all the ide chipset but nothing all the same; then I booted knoppix live cd but also this linux distribution don't enable dma; i tried Mandriva 10.1 the same things; at the end I tried Ubuntu 5.04 but was impossible to boot the live-cd because the distribution didn't see the cdrom (dvdrom). Now I'm downloading kanotix and ......

Finally I apply manually this patch: http://marc.theaimsgroup.com/?l=linux-ide&m=112032992832526&w=2 at the gentoo-sources kernel (adding manually the four line in the piix.c file because the command patch -p0 < ...... didn't work for me), recompiling the kernel without any SCSI and PATA drivers and now dma is working.
Thanks to all.

Now, with the new gentoo kernel is not necessary to apply that patch.
In the kernel 2.6.15-r7 and newer it's sufficient enable SCSI disk support - SCSI generic support - Serial ATA (SATA) support - AHCI SATA support - Intel PIIX/ICH SATA support. In this way the hard disk will be SDA and the cdrom SR0 and the DMA is always on. Remember to change the fstab before rebooting.